Researchers with a wildlife conservation group say they have discovered
thousands of rare Irrawaddy dolphins living in the waters of Bangladesh.

Authors
of a study say they found nearly 6,000 of the endangered freshwater
animals in the Sundarbans mangrove forest and in the adjacent waters of
the Bay of Bengal.

Wildlife protection agencies say before the
study, only small populations of Irrawaddy dolphins were known to
exist, numbering fewer than 200.

The scientists began counting the dolphins in 2004.

The
results were released Wednesday at a marine wildlife conference in
Hawaii, and published in the Journal of Cetacean Research and
Management.

The lead researcher, Brian Smith of the New
York-based Wildlife Conservation Society, said the find "gives us great
hope that there is a future for Irrawaddy dolphins."

In a
statement from the conservation group, he said Bangladesh is an
important sanctuary for the endangered mammals, and "conservation in
this region should be a top priority."

Smith warns that even the
large population of the dolphins in Bangladesh is being threatened by
entanglement in fishing nets, as well as by threats to its freshwater
habitat posed by global warming.

Irrawaddy dolphins can grow to
up to 2.5 meters in length and live in several waterways in southeast
Asia. The animals were declared a threatened species last year by the
International Union for Conservation of Nature and Natural Resources
(IUCN).

In addition to Smith, the study's other authors include
scientists Benazir Ahmed from the Chittagong University zoology
department and Rubaiyat Mansur Mowgli from a Bangladeshi whale and
dolphin research program.